Snapchat – which lets people send photos and videos that
self-delete after between one and 10 seconds after being viewed –
is still a long way behind Facebook (used by 72.5% of US iPhone
owners) and Instagram (36.6%), but Twitter's 26.7% market share
is within Snapchat's sights.

Bear in mind that these figures are for one country and device
only: Snapchat has been installed between 10m and 50m times on
Android smartphones according to the stats on the Google Play
store.

Snapchat's iOS popularity isn't a new trend. Earlier this year,
another analytics company – App Annie – estimated that it was
the
most-downloaded non-game app on iOS globally in May 2013,
overtaking YouTube to top that chart.

Snapchat's funding round in June valued the company at $800m,
despite the fact that the free app has yet to make any revenues
at all: it doesn't include ads or charge its users via in-app
purchases, although it's expected to add the latter in the coming
months.

Dennis Phelps, general partner at Institutional Venture Partners
– one of the companies investing in that round –
claimed at the time that Snapchat's growth was on a par with
some of the biggest existing social networks and apps.

"The growth and engagement metrics are off the charts. Seldom
have we seen a consumer application with this type of user
momentum and excitement," he wrote. "Think Twitter ... Think
Instagram … Think Pinterest … and Snapchat is just getting
started."

Onavo's stats only cover the US, although for now, that's by far
Snapchat's most popular country. Chief executive Evan Spiegel
said at the Dive into Mobile conference in April 2013 that
80% of its users were in the US at that time, with 20% overseas.